CHM 1020 exam 1Rated 100% Correct!!

elements - one of the 100 pure substances in our world from which compounds are formed compound - pure substance made up of two or more different elements in a fixed, characteristic chemical combination mixture - physical combination of two or more pure substances metal - shiny elements, conduct heat and electricity very well metalloids - (8) elements between metals and nonmetals nonmetals - do not conduct heat or electricity well, no one characteristic groups - vertical columns, organized by properties and numbered left to right halogen - Group 7A; fluorine, chlorine, bromine, iodine noble gas - Group 8A; few, if any chemical reactions (argon, helium, radon) ppm/ppb/1% ratio - 1 ppb 1 ppm 1% Risk assessment - process of evaluating scientific data and making predictions in an organized manner about the outcome Toxicity - intrinsic health hazard of a substance